Surface treatment of organic polymers

ABSTRACT

WHICH EXHIBITS IMPROVED LUBRICITY.   (HS-CH2-CH2-CH2-SI(-CH3)2-(O)(1/2))2 (SI(-CH3)-O)N   THE SURFACE CHARACTERISTICS OF VINYLIC POLYMERS ARE ALTERED BY THE APPLICATION OF AN ORGANOSILICON COMPOUND CONTAINING AT LEAST ONE HSR&#39;&#39;SI-MOIETY, WHERE R&#39;&#39; IS A DIVALENT HYDROCARBON RADICAL FREE OF ALIPHATIC UNSATURATION, FOLLOWED BY APPLICATION OF ENERGY. ALTERNATIVELY, THE ORGANOSILICON COMPOUND CAN BE ADDED TO THE MOLTEN VINYLIC POLYMER AND THIS COMPOSITION IS FURTHER PROCESSEC, FOR EXAMPLE, BY EXTRUDING INTO FIBERS. EXEMPLARY IS AN ACRYLONITRILE BUTADIEN STYRENE SURFACE WHICH HAS BEEN TREATED WITH

United States Patent Omce Patented Jan. 4, 1972 3,632,715 SURFACE TREATMENT OF ORGANIC POLYMERS William G. Gowdy, Cherry Hill, NJ, and Joseph W. Keil,

ABSTRACT OF THE DISCLOSURE The surface characteristics of vinylic polymers are altered by the application of an organosilicon compound containing at least one HSRSimoiety, where R is a divalent hydrocarbon radical free of aliphatic unsaturation, followed by application of energy. Alternatively, the organosilicon compound can be added to the molten vinylic polymer and this composition is further processed, for example, by extruding into fibers. Exemplary is an acrylonitrile butadiene styrene surface which has been treated with r r HS CIIzCHCHzSfi 01/2 SIi O Ha -2 0 Ha n which exhibits improved lubricity.

This application is a divisional of application Ser. No. 770,121, filed Oct. 23, 1968 and now US. Patent 3,535,145; which is a divisional of application Ser. No. 507,549, filed Nov. 12, 1965, now US. Patent 3,453,248; which is a continuation-in-part of application Ser. No. 452,921, filed May 3, 1965, now abandoned; which in turn is a continuation-in-part of application Ser. No. 405,570, filed Oct. 21, 1964, now abandoned.

This invention relates to a new method of treating the surfaces of solid organic polymers which have been prepared by vinylic polymerization.

The object of this invention is to provide a means for altering the surface characteristics of these polymers. This invention provides a means for making polymer surfaces which are oleophobic, hydrophobic, hydrophilic, receptive to inks and dyes, having high lubricity, or of low lubricity, as desired.

For example, considering the vinylic polymer polyethylene: solvent-resistant containers can be made from polyethylene which has been provided with an oleophobic surface. Polyethylene having an aminofunctional, hydrophilic surface is receptive to permanent printing and dyeing. Additionally, polyethylene sheets can have their surfaces altered so as to have a high coefficient of friction against other treated polyethylene sheets, making the sheets more easily handleable in bulk.

A great number of other applications are possible with this invention, a number of which are described below.

Most broadly, this invention relates to the process of (1) applying to the surface of a solid, vinylic polymer a film comprising a fluid organosilicon compound, free of aliphatic unsaturation, containing at least one HSRSimoiety, where R is a divalent hydrocarbon radical free of aliphatic unsaturation, and (2) applying energy to the surface of said vinylic polymer, whereby said organosilicon compound is irreversibly attached to said vinylic polymer.

Any solid, vinylic polymer is suitable for use in this invention. By vinylic polymer is meant any organic polymer which is formed by the polymerization of allphatically unsaturated carbon-carbon bonds, s'i1ch as those found in the vinyl group. Examples of such polymers are polyethylene, polypropylene, poly(acrylonitrile-butadiene-styrene), polystyrene, polymethylmethacrylate, poly- (acrylonitrile-styrene), polyisobutene, polyvinyl chlpride, polyvinylacetate, poly(vinylchloride-vinylidene chloride), and the organic rubber such as natural rubber, ethylenepropylene-cyclohexadiene terpolymer, styrene-butadiene rubber, and butadiene-acrylonitrile rubber.

R can be any divalent hydrocarbon radical, free of aliphatic unsaturation, such as the methylene, dimethylene,

trimethylene, isobutylene CH2 (-CH2(BHOH2 hexamethylene, octadecamethylene, cyclohexylene,

-on, -om HGHr-, or omOomomradicals. The isobutylene, trimethylene, and dimethylene radicals are especially desirable.

The organosilicon compound must be fluid, e.g. it must be a liquid, a vapor, or applied as a solution of an emulsion.

The nature of the organosilicon compound used in this process is not critical, so long as there is at least one HSRSi moiety present in the molecule. The nature of the surface produced on the vinylic polymer varies with the type of organosilicon compound used.

For example, the organosilicon compound can be a hydrolyzable organosilane. One embodiment of this invention is the process of (l) applying to the surface of a solid, vinylic polymer a film consisting essentially of a composition selected from the group consisting of (a) silanes of the formula (HSR),,,R,,SiX., and partial hydrolyzates thereof, where R is selected from the group consisting of monovalent hydrocarbon and halohydrocarbon radicals free of aliphatic unsaturation, R is a divalent hydrocarbon radical free of aliphatic unsaturation, m has an average value of 1 to 3, n has an average value of 0 to 2, the sum of m and n being from 1 to 3, and X is selected from the group consisting of the hydroxyl group and hydrolyzable groups free of aliphatic unsaturation; and (2) applying energy to the surface of said vinylic polymer, whereby (a) is irreversibly attached to said vinylic polymer.

R can be any monovalent hydrocarbon or halohydrocarbon radical free of aliphatic unsaturation such as the methyl, ethyl, isobutyl, cyclohexyl, octyl, tetradecyl, octadecyl, phenyl, diphenyl, Z-phenylpropyl, tolyl, 3,3,3-trifluoropropyl, 4-chlorooctyl, bromocyclohexyl, dichlorophenyl, or bromophenyl radicals. Examples of R are shown above.

More than one type of R or R group can be found in the silicones used in this invention.

X can be any hydrolyzable group, free of aliphatic unsaturation, known to the art, e.g., alkoxy groups such as methoxy, ethoxy, isopropoxy, hexoxy, or 2-ethylhexoxy; halogen groups such as chlorine or bromine; acyloxy groups such as the formate, acetate, or butyrate groups; ketoxime groups such as or the isocyanate group.

Examples, therefore, of suitable silanes for use in this invention are Hs -Si ONC CH; 2 02m 2 H S CHCHQSi(OCCHK)Z H s CH(CHz)10SiNC O, and

HSOHgCHCHz-Sl( CH Silanes containing no hydrolyaable groups such as HS CH CHCH SKCH h are also usable in this invention to provide a hydrophobic surface.

Energy can be applied to the vinylic polymer surface, in accordance with step (2) of the above-described process, in a number of ways. The method of applying the energy is not critical, though some methods give better results than others.

The vinylic polymer surface can be heated in the absence of air to provide adequate energy to cause the organosilicon compound to permanently bond to the vinylic polymer.

Another preferred method of applying energy is to apply ultraviolet radiation to the solid vinylic polymer surface which has the organosilicon compound thereon. There is a specific ultraviolet dosage for each vinylic polymer-siloxane system that gives the best results for the desired purpose. There is no known way to theoretically calculate this optimum dosage for a given system, but some workable dosages are shown in the examples below. Effective dosages generally lie between 5 and 40 minutes if the organic polymer is 6 inches from a standard ultraviolet lamp.

Other methods of applying energy are through the use of gamma radiation, or peroxide catalysts coupled with heat.

Upon the application of energy to the vinylic surface which is silicone-coated, it is believed that the mercaptan groups on the organosilicon molecules react With linkages in the vinylic polymer in the following manner to form a chemical bond between the polysiloxane and organic polymer:

After this reaction, the organosilicon compound is believed to be chemically attached to the vinylic surface so that washing with solvents for the organosilicon compound cannot remove them. Such solvent-washing is a good test for Whether or not the silicone is actually bonded to the vinylic polymer.

The process of treating vinylic polymer surfaces with the above-described hydrolyzable silanes finds an important utility as an intermediate step in the preparation of altered surfaces on vinylic polymers. An example of this is the process of (1) applying to the surface of a solid, vinylic polymer a film consisting essentially of a composition selected from the group consisting of (a) silanes of the formula (HSR-) R SiX and partial hydrolyzates thereof, Where R is selected from the group consisting of monovalent hydrocarbon and halohydrocarbon radicals free of aliphatic unsaturation, R is a divalent hydrocarbon radical free of aliphatic unsaturation, m has an average value of 1 to 3, n has an average value of 0 to 2, the sum of m and n being from 1 to 3, and X is selected from the group consisting of the hydroxyl group and hydrolyzable groups free of aliphatic unsaturation, (2) applying energy to the surface of said vinylic polymer, whereby (a) is irreversibly attached to said vinylic polymer, and (3) applying to the same surface of said vinylic polymer a film of (b) a composition selected from the group consisting of and partial hydrolyzates thereof,

Xi-m-nsuivNuo and partial hydrolyzates thereof, silicic acid, and partial condensates of silicic acid, where R" is any alkylene radical of no more than 4 carbon atoms, x is a positive integer, Q is selected from the group consisting of hydrogen and R"NH groups, and the other symbols are as defined above.

R" can be any alkylene group as described above, such as methylene, dimethylene, trimethylene, and

These materials of (b) above as believed to react with the hydrolyzable groups of the mercapto silanes of (a), thereby being bonded to the surface of the vinylic polymer. The materials of (a) and (b) can be added to the vinylic polymer simultaneously, if desired, preferably in proportions of 1 to 75 mol percent of (a) and 25 to 99 mol percent of (b).

The compositions of the formula and their partial hydrolyzates, impart oleophobicity to the vinylic polymer surface when applied in the manner described above. x preferably has a value of 4 to 14.

The compositions of the formula Xi-m-n sunmno and their partial hydrolyzates, render the vinylic polymer surface hydrophilic. Water-soluble dyes, inks, and printing pastes, such as polyamide resins that contain pigments, can be permanently affixed to such a treated surface, making possible the dyeing of thermoplastic fibers and printing on thermoplastic sheets.

Finally, silicic acid and the partial condensates thereof dry on the polymer to produce what is essentially a silica surface bonded to the vinylic polymer. This increases the coefficient of friction of the vinylic polymer, which is useful where sliding is undesirable.

Another useful additive to the mercaptosilane-treated surface of a vinylic polymer is a polyglycol which is endblocked with a functional group that reacts with the hydrolyzable groups on the vinylic polymer surface. Hydrophilic or slightly hydrophobic surfaces can be produced in this manner.

Catalysts can be used to accelerate the reaction of the above materials with the mercaptosilane-treated surface if desired, e.g., KOH, FeCl stannous octoate, trihexylamine, and other known catalysts for the hydrolysis and condensation of silanes that contain hydrolyzable groups.

The term applying to the surface carries with it the requirement that the organosilicon compound so applied should be found on the surface in detectable amounts, e.g. as a film of polysiloxane.

The organosilicon ingredient can be applied to the vinylic polymer surface in a direct or an indirect manner; in other works, not only can the organosilicon ingredient be directly applied by conventional means to the surface of the vinylic polymer, but it can also be added to the molten vinylic polymer so that it is dispersed therein. This latter technique is particularly useful with saturated hydrocarbon polymers, e.g. polypropylene.

A particularly useful product of this latter technique is a composition consisting essentially of a mixture of (a) 100 parts by weight of a thermoplastic, saturated vinylic polymer and (b) from 0.01 to 1.4 parts by weight of an organosilicon compound selected from the group consisting of silanes of the formula (HSR') R,,SiX and partial hydrolyzates thereof, where R is selected from the group consisting of monovalent hydrocarbon and halohydrocarbon radicals free of aliphatic unsaturation, R is a divalent hydrocarbon radical free of aliphatic unsaturation, m has anaverage value of l to 3, n has an average value of to 2, the sum of m and n being from 1 to 3, and X is selected from the group consisting of the hydroxyl group and hydrolyzable groups free of aliphatic unsaturation.

It has been found that these compositions are surfacereactive in the manner of the various mercaptoalkylsilanecoated, saturated polymers shown above, and that surface properties similar to those shown above can be attained. These compositions also tend to have higher heat distortion temperatures and more resistance to cold fiow than their mercaptoalkylsilane-free counterparts. They also ap pear to exhibit other improvements in physical properties as well as those mentioned above.

The above compositions can be utilized to make dyeable fibers by the process of (l) Extruding one of the above mercaptoalkylsilanecontaining vinylic polymers into fibers and (2) Applying to said fibers a water dispersion containing from 0.1 to 50 weight percent of a priming composition selected from the group consisting of colloidal silica, a silane of the formula and partial hydrolyzates of said silane, where R is selected from the group consisting of monovalent hydrocarbon and halohydrocarbon radicals free of aliphatic unsaturation, R" is an alkylene radical of no more than 4 carbon atoms, X is selected from the group consisting of the hydroxyl group and hydrolyzable groups, Q is selected from the group consisting of hydrogen and R"NH groups, m has an average value of 1 to 3, and n has an average value of 0 to 2, the sum of m and n being from 1 to 3, whereby a dyeable fiber is produced.

Examples of the various symbols and ingredients are shown above.

It should be noted that the aminoalkylsilane or its hydrolyzates, which must be present in order to render the fiber dyeable, must be applied Within a few minutes or hours after preparation of the mercaptoalkylsilane-containing vinylic polymer. If this does not happen, the vinylic polymer will often become nonadherent to the aminoalkylsilane and therefore not permanently dyeable.

Alternatively however, a dispersion of colloidal silica can be applied to the silane-containing vinylic polymer. The vinylic polymer will then remain adherent indefinitely toward all organosilicon compounds which contain silanol or hydrolyzable groups, including the aminoalkyl silanes used herein. The mercaptoalkylsilicone-containing fibers can therefore be stored for a long time and/or heated without the problem of degradation of the aminoalkylsilane primer on its surface. They can then be later treated with the aminoalkylsilane and dyed.

The preferred vinylic polymers for making fibers as described above are polyethylene, polypropylene, and copolymers thereof.

The above process can be commercially exploited by adding the mercaptoalkylsilane ingredient, or its hydrolyzate, to the molten hydrocarbon polymer prior to extrusion, and by placing the colloidal silica or the aminoalkyl silicone into the quenching bath into which the fibers are immediately drawn after extrusion. Only a few minor modifications are therefore required to adapt the presently existing production lines for hydrocarbon polymer fibers to perform the process of this application.

Another embodiment of this invention is the process of (1) applying to the surface of a solid, vinylic polymer a film of a fluid siloxane polymer having a viscosity of at least 45 cs. at 25 C., which consists essentially of (a) (R,,SiO units and (b) [HSR'-) R SiO units, where R is selected from the group consisting of monovalent hydrocarbon and halohydrocarbon radicals free of aliphatic unsaturation, R is a divalent hydrocarbon radical, free of aliphatic unsaturation, n has an average value of from 1.8 to 2.2, m has an average value of 1 to 3, and k has an average value of 0 to 2, the sum of m and k being no more than 3, and there being an average of at least 2 (b) units and at least 5 times as many (a) units as (b) units per siloxane polymer molecule; and (2) applying energy to the surface of the organic polymer, whereby the siloxane polymer is attached to 7 the vinylic polymer surface, forming a permanent lubricant thereon.

By permanent it is meant that siloxane coating cannot be washed off the vinylic polymer with a solvent for the siloXane without also removing the outer surface of the organic polymer.

The fluid siloXane polymer generally needs a viscosity of at least 45 ca. at 25 C. in order to keep from soaking into the organic polymer, thereby leaving the polymer surface, but some organic polymers, lower viscosity siloxanes can be used.

The upper viscosity limit of the siloxane is not critical, the only requirement being that the siloxane be spreadable on the organic polymer. It is preferred, however, for the siloxanes used to have a viscosity of below 5000 ca. at 25 C.

It is also preferable in this case for the organic polymer to be an organic rubber, examples of which have been given above. Examples of R and R are also shown above.

The preferred siloxane is a linear dimethylsiloxane polymer with 01-1 (OS iRSH) 6H.

groups as endblocking units.

It is also especially preferred for the siloxanes used to have viscosities of 100 to 1,000 ca. at 25 C.

A preferred method of applying energy to mercaptosiloxane-treated polymers is to heat the organic polymer, preferably rubber, to the vulcanizing temperature in a mold, using the polysiloxane of this invention as a mold release fluid. The resulting product is a vulcanized, molded article with permanent lubricity on its surface due to the fact that at least some of the siloxane is bonded to the organic polymer.

Little difficulty with the silicone concentration will be encountered if it is placed on the vinylic polymer in pure, undiluted form; however, solutions and emulsions can often be used to apply the silicone to the vinylic polymer surface.

The mercaptosilicones of this invention are generally known to the art, and can be made in a number of ways.

Mercapto-endblocked polysiloxanes can be made by equilibrating cyclic polysiloxanes containing the desired R groups with a mercapto-disiloxane of the formula in the presence of an acid clay catalyst, where the symbols are as defined above.

The above-mercapto-disiloxanes can be made by hydrolyzing the appropriate mercapto-silane containing a silicon-bonded hydrolyzable group such as the chlorine group.

Another way of making mercapto-endblocked polysiloxanes is to react hydroxyl-endblocked polysiloxanes containing the desired R groups with a compound of the formula where R and R are defined above, in the presence of stannous octoate. Methanol is evolved as a byproduct.

A way of making any mercapto-siloxane used in this invention is to cohydrolyze silanes containing only r groups and hydrolyzable groups with silanes containing RSH groups, or to equilibrate cyclic siloxanes containing only R groups with polysiloxanes containing RSH groups.

The mercaptosilanes, which can be used by themselves or which can be used to make the mercaptosiloxanes of this invention, can be made as follows: when it is desired for the mercapto group to be separated from the Si atom by 1 or 3 carbon atoms, the appropriate terminal chloroalkyl compound can be reacted with NaSI-I e.g.:

When it is desired for 2, 4 or more carbon atoms to separate the mercapto group from the silicon atom, the appropriate terminal olefin can be reacted with thioacetic acid, e.g.

OH; 0 CH3OS iCH=OH2 orn o sn on, a

on. onaosiorncnzsdorn onaon on Na A on CH3 0 onaosiomomsn emotion,

Other known methods also exist for making the above silanes.

The following examples are illustrative only and should not be construed as limiting the invention which is properly delineated in the appended claims.

EXAMPLE 1 The following rubber formulation was prepared in having a viscosity of about 50-60 cs. at 25 C., was used in the following experiment.

The lubricity of the rubber samples was tested by the Crock test where a /2 inch ball bearing is rubbed back and forth in a 6 inch path at about 60 strokes per minute, the weight of the ball bearing on the rubber being 1.5 pounds. The time of failure is the time until the rubber begins to crack and abrade.

(a) The above rubber formulation was vulcanized for 45 minutes at C. and 5,000 p.s.i. It was then wiped with isopropyl alcohol. After 5 minutes of the Crock test, the rubber showed severe abrasion.

(b) The above rubber formulation was vulcanized as in (a), and then the polyniloxane was applied. The treated rubber withstood 4 hours on the Crock tester without abrasion. However, similarly treated rubber was cleaned with isopropyl alcohol and tested on the Crock tester. After 5 minutes, there was severe abrasion.

(c) The above rubber formulation was vulcanized as in (a), but the polysiloxane was used as a mold release agent. The vulcanized rubber was cleaned with isopropyl alcohol and tested on the Crock tester. After 4 hours there was moderate abrasion on the rubber.

(d) The above rubber formulation was vulcanized for 1 hour at 175 C. and 5,000 p.s.i., using the above siloxane as a mold release agent. The vulcanized rubber was cleaned with isopropyl alcohol and treated on the Crock tester.

a mold release agent, the polymer containing about 150 dimethylsiloxane units. The rubber samples were then washed with isopropyl alcohol.

The lubricity and strength characteristics of each sam- After 4 hours there was no abrasion on the rubber. 5 ple follow:

TABLE Crock test Durom- Tensile Elongation, time to Rubber Treatment eter (p.s.i.) percent failure Natural None 81 2,060 510 sec.

Do Siloxane mold release 85 2, 010 500 4 hr. 30 min. Ethylene propylene cy hexadlen one 91 3,260 510 30sec.

D Siloxane mold release. 90 3,180 500 24 hr. Styrene-butadiene rubber mixed w on 87 2, 515 520 1 min. Do 88 2, 550 510 12 hrs. Butadiene'acrylonitrile (high nitrile)... 97 3, 550 285 2 min.

D Siloxane mold release 07 8, 450 290 8 hrs.

one 83 3,860 400 1min. Siloxane mold release 85 3, 680 410 24 hrs. one 88 1,850 650 20sec.

87 1,800 675 min. 84 2,910 500 sec. 85 3,000 535 35 min.

(e) The rubbers of (a) and (c) were tested for their 25 EXAMPLE 3 physical characteristics with the following results:

Standard formulations of the following rubbers were prepared. Samples of each were vulcanized for 45 minutes at 160 C. and 5,000 p.s.i., and with one sample of each a mercaptomethyl endblocked dimethylpolyrubber Standard formulations of the following rubbers were Tensile vulcanized as in Example 2 with the polysiloxanes shown strength at Elongation Rubber Durometer break point percent; below used as mold release agents. The polysiloxanes and (a) 2 650 530 30 rubbers used, and the lubricity obtained, as shown below. (6:11:11: 2:880 700 The samples were washed in isopropyl alcohol before testing in the Crock tester (described in Example 1).

TABLE Crock test time to Rubber Siloxane Polymer failure (a) Styrene-butadiene rubber CH CH CH3 cs. at 25 CJ... 4 hrs.

mixed with polybutadiene.

H|iO(S10)nSiH CH CH CH (1)) Styrene'butadiene rubber CH CH3 CH 52 cs. at 25 C 12 hrs.

mixed with polybutadiene.

HS CHgSiO(SlO)-2oSiCH2SH H3 H H:

(c) Styrene-butadiene rubber CH CH CH 400 cs. at 25 C.-. 12 hrs.

mixed with polybutadiene.

HSCH 1O(S1O)-1 uS1CH SH CH CH CH (d) Ethylene-propylene-eyclo- The siloxane of (a) 1 hr.

hexadiene terpoly'mer. (e) Ethylene-propylene-eyclo- The siloxane of (c) 24 hrs.

hexadiene terpolymer. (f) Styrenebutadiene rubber. The slloxane of (a) 1 min. (g) Styrene-butadiene rubber. The siloxane of (b).. 1 hr. (11) Styrene butadiene rubber... The siloxane of (c) 1 hr. (i) Styrenc-butadiene rubber (IE (IE CH 400 cs. at 25 C 3 hrs.

(HS CHzCHCH2SiO1/2)2(SiO)-i5n CH CH (j) Butadiene-aerylouitrile rubber The siloxane of (a) 3 hrs.

(low uitrile). (k) Butadiene-acrylonitrlle rubber The silox ane of (b) 24 hrs.

(low nitrile). (l) Butadiene-aerylonitrile rubber The siloxane of (c) 24 hrs.

1 This is a comparison run. It and the others below show the superiority of mereaptosiloxaues to a siloxane containing the SH1 functional group.

EXAMPLE 2 EXAMPLE 4 The following vulcanized rubber samples were thinly coated with mercapto-siloxanes and treated with ultraviolet light from a standard U.V. lamp. The irradiated products were washed in isopropyl alcohol and tested by siloxane with a viscosity of 400 cs. at 25 C. was used as 75 the Crock test of Example 1. The results follow:

TABLE Crock itest Rubber Siloxane used Irradiation fgi isrg (a) Natural. N n None 20 SW (b) Natural CH3 CH3 CH3 440 as. at 25 min. of ultraviolet, 6 in. from 15 I I I U.V. source. (HS CH2CHCI'IzSiO1/2)2(SiO)n CH OH;

( Natural The siioxane of (b) 16 min. of ultraviolet, 6 in. from 4 hrs.

U.V. source.

(11) Natural CH3 CH3 51 05- at 25 0..... 15 min. of ultraviolet, 6 in. from 4 hrs.

I I U.V. source.- (HS CH2SiOi/2)2( S10)n CH: C H3 (e) Styrenc-butadiene rubber. N None 45 sec. (i) Styrene-butadiene rubber The siloxane of (b) min. of ultraviolet, 6 in. from 5 in.

U. source. (g) Styrene-butadiene rubber Th siloxan of (b) 30 of ultraviolet, 6 in. from 30 min.

. source. (b) Ethylene propylene-cyclohexadiene None None- 30 sec.

tel-polymer. Ethylenepfopylene cyclohexadiene The siloxane of (b) 5 min. o ultraviolet, 6 in. from 10 minterpolymer. U.V. source.

Ethylenepropylene cyclohexadienc The siloxane of (b) 30 min. of ultraviolet, 6 in. from 16 hrs.

terpolymer. U.V. source. (k) Ethylenepropylene cyclohexadiene The siloxane of (d) 30 min. of ultraviolet, 6 in. from 1 hr,

terpolymer. U.V. source. Styrene-butadiene rubber with poly- None None 1 min.

butadiene. (m) st renebutadiene rubber with poly- The siloxane of (b) 15 min. of ultraviolet, 3111. from 5 min.

butadiene. U.V. source. (n) Styrene-butadiene rubber with poly- The siloxane of (b) 30 min. of ultraviolet, 3 in. from 1 min.

butadiene. U.V. source. (0) st rene-butadiene rubber with poly- The slloxane of (b) 30 min. of ultraviolet, 6 in. from 30 min.

butadiene. I U.V. source. (p) Styrene-butadiene rubber with poly The siloxane of (b) 1 hr. of ultraviolet, 6111. from 2 i i butadiene. U.V. source. ((1) Buty1 Non Non sec. (1) Buty1 The siloxane of (d) min. of ultraviolet, 6 in. from 1 rain;

U.V. source.

I This indicates that there has been an overdose of ultraviolet.

2 The pull needed to remove Scotch tape from the rubber of (q) was 750 gms. The pull needed to remove Scotch tape from the rubber of (r) was about half of this 400 gms. This clearly indicates the presence of a surface lubricant.

EXAMPLE 5 EXAMPLE 6 When natural rubber is coated with a fluid polysiloxane Steel Panels Pnmgd Wlth consisting essentially of 40' mol percent (CH O) SiCH CI-I CH NHCH CH NH were bonded to films of polyethylene or acrylonitrilebutadiene styrene which were 3 to 5 mils thick.

To the thermoplastic faces of these panels there were (sio added films of the mercapto-siloxanes shown below, and A the panels were irradiated with ultraviolet light. They were then wiped with isopropyl alcohol and tested to units: 11101 Percent failure in the Crock test of Example 1. 311; The results follow: 55 (hi0) TABLE Crock test Substrate Siloxane used Irradiation g g g (a) Polyethylene Non None (b) Polyethylene D methylpolyslloxane 350 cs. at 25 C -.do. fiifi:

r r a (c) Polyethylene. (HS HzCHCHzS|1O1/2)-2 S10 440 05. at 25 C d0 5 min.

CH3 1 H: n

(1 Polyethylene The siloxane of (c) 5 min. or U.V. light, 6 in. from 10 min.

U.V. source. (e) Polyethylene- The Siloxane of (C) 15 min. of U.V. light, 6 in. from 35 min.

. U.V. source. (t) Acrylorutr le-butudicno styrene None None 5min (g) Acryioiut lo butadicnc styrene The siloxanc of (c) 15 min. of U.V. light, 6111. from 22 min.

U.V. source.

13 units, and mol percent [HSC H SiO units, there being an average of 2 mercaptosiloxy groups per molecule, a rubber possessing permanent lubricating characteristics at its surface is formed on exposure of the coated rubber to about 2 megarads of gamma radiation in the period of an hour.

EXAMPLE 7 When crystalline polypropylene resin is coated with a fluid polysiloxane consisting essentially of approximately 69 mol percent CH3 (S iO) 6H.

units, 25 mol percent (SiO) u 2s units, 1 mol percent (CH SiO units, 2 mol percent 0H3 OS:lCH3uSH) units and 3 mol percent (7H3 i I/2 iC1BH30SH)g] units, having a viscosity of 5,000 cs. at C., and when this coated resin is heated at 150 C. with infrared radiation in argon gas for one hour, a permanent lubricating coating on the surface of the resin is formed.

EXAMPLE 8 When solid ethylene-vinyl acetate copolymer is coated with a fluid polysiloxane of the average formula (3H3 (IJHS (CH C CHiOHzSiO 2 s10 S II (3113 2 and exposed to ultraviolet light for 20 minutes at a 6 inch distance from the UV. source, the resin acquires permanent lubricity.

EXAMPLE 9 When polystyrene resin is coated with a fluid polysiloxane of the average formula (1H3 (HS- S Si01/2 SiO CH2 H2 l H2 CH: CFa 2 CH3 70 and exposed to minutes of ultraviolet light at a 6 inch distance from the U.V. source, the resin acquires permanent lubricity.

EXAMPLE 10 A 1 weight percent solution of a partial hydrolyzate of HSOH2CH2S1 0CH3 Z in toluene was wiped on polypropylene yarn of 210 denier and count. This was then dried in the air and exposed for 10 minutes to an ultraviolet lamp at a distance of 3 inches.

Following this, a 10 weight percent solution of in isopropanol was wiped on the yarn, and the yarn was dried at 260 F. for 5 minutes.

with the mercaptosilane hydrolyzate, but including the treatment with the aminosilane.

The dye could be removed from this second sample of yarn by hand-washing with warm, soapy water.

EXAMPLE 11 (a) A thin film of HS oHn JHomsuoom),

was wiped on a sheeet of polyethylene, which was then exposed for 10 minutes to an ultraviolet lamp at a distance of 3 inches.

A thin film of 3,3,3-trifluoropropyltrimethoxysilane was then applied to the treated polyethylene surface, and allowed to stand for a few minutes. The surface was then washed with acetone to remove unattached silanes and allowed to dry.

The contact angle of a drop of mineral oil on the treated polyethylene surface was 20. This indicated moderate oleophobicity.

The contact angle of a drop of mineral oil on an untreated polyethylene surface was found to be 0, indicating no oleophobicity.

The contact angle of a liquid drop on a surface is the angle between the surface and the side of the drop where it contacts the surface, and is a measure of the compatibility of the materials that make up the drop and the surface.

(b) The above experiment was repeated, replacing 3,3,3-trifluoropropyltrimethoxysilane with The contact angle of a drop of mineral oil on polyethylene treated in this manner was 45 indicating strong hydrophobicity.

(c) A polyethylene container was treated in the manner of (b) above, and was found to be suitable for containing oils for a long period of time.

EXAMPLE 12 A thin film of HSOHzCFHCHzSKOCHQ;

was wiped on a sheet of polyethylene, which was then exposed for 10 minutes to an ultraviolet lamp at a distance of 3 inches. Treated sheets of mercaptosilane-grafted polyethylene resulted.

A thin film of was wiped on the treated polyethylene and dried.

To this there was applied a polyamide coating resin which is useful as a printing paste (Versamide 940). The adhesion of the resin to the coated polyethylene was excellent, with no adhesive failure under severe flex.

The experiment was repeated, omitting the mercaptosilane treatment, but including the treatment with the aminosilane.

The adhesion of the polyamide coating resin to the polyethylene was poor.

EXAMPLE 13 Two polyethylene sheets, treated with mercaptosilane as in Example 12, were coated with an aqueous dispersion of colloidal silica (a partial condensate 0f silicic acid), and were then allowed to dry. They were then washed in water to remove excess silica and dried again.

The sheets were placed on top of each other with their treated sides in contact, and a 125 g. weight was placed on top of both.

The upper sheet was then pulled laterally along the bottom sheet. 120 g. of force was required to start the sheets moving, indicating that the treated surfaces had a starting coefiicient of friction of 0.96.

Untreated polyethylene sheets, when tested as above, began moving relative to each other at 65 g. of pull, showing that their starting coeflicient of friction was 0.52.

The treated polyethylene sheets of Example 12 showed a coeflicient of friction of 0.36 upon similar testing.

EXAMPLE 14 The mercaptosilane-treated polyethylene of Example 12 was treated with an ethylene-propylene polyglycol copolymer (Pluronic L 61) which was endblocked by reaction with When a ring of butadiene-acrylonitrile rubber is coated with and dried in the presence of ultraviolet radiation, coating of the same ring with any of the following compounds, in the presence of gentle heating, will result in an oleophobic rubber ring which is resistant to swell in organic solvents:

C F CH2CH2SiC1 A partial hydrolyzate of (C F CH CH )Si(OC H CzHs (CF CiHzCHzhSlONC A partial hydrolyzate of omiacmomsxo CH EXAMPLE 16 When a mixture of 100 parts by weight of molten poly of ultraviolet radiation with I ll nssi-o OCH:

CzHs which is cocondensed with any of the following compounds, polystyrene strips which are receptive to water soluble dyes and inks are produced:

(CH O) SiCH CH CH NH A partial hydrolyzate of (C11 0):SlCHgCHzCHzNHCHzCHzNHz EXAMPLE 17 (a) To 2 samples of molten polypropylene there was added 0.1 and 0.5 weight percent, respectively, of

HSCH CH Si (OCH 3 The silane was dispersed in the ploypropylene, and the mixture was extruded into fibers. The fibers were immediately quenched in a 1.7 weight percent water solution of NH CH CH NH(CH Si(OCH The treated, dried fibers were washed in isopropanol, dried and dipped in a 1 weight percent water solution of Cibalon Red 2 GL dye. The fibers were then dried for 5 minutes at 260 F. to yield a richly-colored polypropylene.

The dyed fibers were washed for three automatic washer cycles with hot water and Tide detergent. The color of both sets of fibers was unfaded at the termination of this treatment.

(b) The above experiment was repeated using polypropylene without a mercaptoalkylsilane. The dyed fibers made from this material faded badly during the washing test.

EXAMPLE 18 The experiment of Example 18 (a) was repeated, using a molten polypropylene which contained 0.5 weight percent of a hydrolyzate of HSCHRCHZSi 0 CH3) 2 The same excellent results as above were achieved.

EXAMPLE 19 When a mixture of parts by weight of molten polypropylene and one part of is extruded into fibers which are quenched in a 5 weight percent emulsion of colloidal silica, the resulting fibrous product exhibits excellent fastness to water-soluble dyes when they are treated shortly before dyeing with NH CH CH CH Si (OCH 3 EXAMPLE 20 When strips of polystyrene are treated in the presence (ethylene-propylene) copolymer and one part by weight of 17 is extruded into fibers which are then dipped in a 20 weight percent water solution of a partial hydrolyzate of The resulting fibrous product is permanently dyeable with water-soluble dyes.

That which is claimed is: 1. The process of (1) extruding into fibers a molten composition of (a) 100 parts by weight of a vinylic polymer, and (b) from 0.01 to 1.4 parts by weight of an organosilicon compound selected from the group consisting of silanes of the formula and partial hydrolyzates thereof, where R is selected from the group consisting of monovalent hydrocarbon and halohydrocarbon radicals free of aliphatic unsaturation, R is a divalent hydrocarbon radical free of aliphatic unsaturation, m has an average value of 1 to 3, n has an average value of to 2, the sum of m and n being from 1 to 3, and X is selected from the group consisting of the hydroxyl group and hydrolyzable groups free of aliphatic unsaturation.

(2) applying to said fibers a water dispersion containing from 0.1 to 50 weight percent of a priming composition selected from the group consisting of colloidal silica, a silane of the formula is a hydrocarbon polymer.

6. The process of claim 4 where the hydrocarbon polymer is selected from the group consisting of polyethylene, polypropylene and copolymers thereof.

References Cited UNITED STATES PATENTS 3,170,940 2/ 1965 Johnston 260448.2 3,186,965 6/1965 Plueddernann 260--46.5 3,278,484 10/1966 Tesoro 26046.5 3,312,669 4/ 1967 Giordano 26079.1 3,317,461 5/1967 Plueddemann 26046.5 3,512,915 5/1970 Spier 88 JAY H. WOO, Primary Examiner US. Cl. X.R. 

